1. Field of the Invention
The present invention relates to material requirement planning systems and methods, and particularly to a master production scheduling management system and method.
2. Background of the Invention
Master production schedules (MPSs) are vital for all manufacturers, especially large-scale manufacturing enterprises. An MPS is a production schedule for finished products spanning a period of time in the future. The aim of the MPS is to timely forward the finished products to relevant customers, while avoiding overloading or underutilization of production apparatus and production capacity. Usually, a manufacturer makes purchase orders for necessary raw materials and components according to production demand, buffer inventory and lead time, and transmits the purchase orders to corresponding vendors. The vendors provide the raw materials and components to the manufacturer according to the purchase orders. Changes in market supply and demand cause much uncertainty in production demand, and purchase orders frequently need to be changed or re-scheduled. If the purchase orders are not re-scheduled methodically and timely, this can lead to delays in supply of the raw materials and components, and consequent delays in production.
China Patent No. CN1277401A, published on Dec. 20, 2000, discloses a purchase order producing system. The system is executed on a computer that comprises a storage and a processor. The system comprises: a demand database for recording demand for material in each week of a predetermined period; a buffer inventory module for calculating an average demand in each week, and for calculating a buffer inventory that should be maintained at the end of each week based on the average demand; and a purchase order module for generating purchase orders for each week based on the average demand of the week, on-hand inventory and the buffer inventory.
The above-mentioned purchase order producing system can meet demand for material only to a limited extent; that is, according to weekly cycles. The system cannot generate purchase orders according to more up-to-date production demand and material demand. Nowadays, production demand can fluctuate even daily, so that a manufacturer can quickly respond to a customer's new requirements. If material demand cannot be changed quickly to support a new production demand, the manufacturer runs the risk of late or inefficient production, having an unsatisfied customer, or even losing a customer.
Thus, a system and method is needed for managing master production scheduling, by use of which a manufacturer can simulate production capacity and material demand to make suitable MPSs, and reschedule the MPSs as needed to respond to customers' new requirements.